This invention relates to the field of safety handrails for the construction of buildings and in particular to stanchions for such handrails for releasable mounting to modular concrete slab walls.
Judging by the plethora of prior art relating to safety rails which may be mounted onto building roofs, it would appear that there is a recurring safety problem of workers falling from the roofs of buildings which are under construction or which are having their roofs repaired or upon which other work is being performed. Obviously, these accidents occur when the workers are moving about, and it is believed, especially when the workers are carrying materials on the roof and are required to work near the edges of the roof.
As documented in the prior art, the magnitude of this workplace hazard has drawn the attention of regulatory bodies including the Occupational Safety and Health Administration in the United States, the Department of Occupational Safety and Health in Canada, and, as applicant is aware, the Workmen""s Compensation Board in British Columbia, Canada. The prior art reports that in some, if not all jurisdictions, some form of barrier is now required around roof edges in the workplace.
Various attempts of which applicant is aware have been made in the prior art in the field generally of portable roof guard rail supports. Applicant is not, however, aware of any prior art specifically relating to the application of the present invention, that is, a removable mountable rail stanchion for use on modular concrete slab walls. However, in the general field, applicant is aware of U.S. Pat. Nos. 3,995,834 which issued Dec. 7, 1976, to Melfi for Supports for Guard Rails, and U.S. Pat. No. 4,669,577 which issued Jun. 2, 1987, to Werner for Slab Clamp Guard Rail Post. Both Melfi and Werner teach the mounting of guard rail stanchions onto a generally horizontal deck or like member by means of clamps. Neither teach nor suggest, nor are adaptable to provide the simplicity and usefulness of the stanchion of the present invention.
Applicant is also aware of U.S. Pat. No. 5,377,958 which issued Jan. 3, 1995, to Palmer for a Safety Railing System. Palmer discloses vertically extending stanchion members mounted to wall brackets by means of pivoting links. The pivoting links swing outwardly upon impact on the railing to distribute the load applied along a wall bracket. The wall bracket is mounted below the exterior facia of the wall by fasteners driven through the brackets into the underlying wall structure. Again, the simplicity and usefulness of the present invention in this application to concrete wall structures is neither taught nor suggested.
Applicant is also aware of prior art relating to safety rails mountable onto pitched roofs, two examples of which are U.S. Pat. No. 5,647,451 which issued Jul. 15, 1997, to Reichel for a Portable Roof Guard Rail Support Device, and U.S. Pat. No. 5,573,227 which issued Nov. 12, 1996, to Hemauer for a Guardrail Stanchion Mounted Onto Building Frame. As with the Palmer reference, both Reichel and Hemauer provide structures designed to distribute the load of a falling worker by various attachment means to the roof, facia, and underlying rafters.
Applicant is also aware of U.S. Pat. No. 4,003,541 which issued Jan. 18, 1977, to Lanier for a Portable Decking Form. Lanier teaches a decking form for the construction of modular housing units having a monolithic slab roof. As part of that teaching, Lanier makes use of vertical stanchions to support railings around the circumference of the roof, where the stanchions are slidably connected into channel bases secured to the roof I-beams. However, the advantages of the present invention relating to modular concrete slab walls are neither taught nor suggested.
Also taught for use on generally horizontal planar roofs is the Support for the Handrail of a Detachable Handrail Unit disclosed in U.S. Pat. No. 4,909,483 which issued Mar. 20, 1990, to van Herpen. The handrail supports of van Herpen include a base which is kept in place on the roof by use of a weight, and a post which is connected to the base, the base and the post interconnected by a horizontal hinge. A structure is provided for locking the base and post relative to each other so that the post is in a generally vertical handrail supporting position.
Applicant is further aware of Australian patent No.141,378 which issued May 28, 1951, to Green for a Wire Fence Fastener; U.S. Pat. No. 4,015,827 which issued Apr. 5, 1977, to Brand for a Support Stanchion; U.S. Pat. No. 2,734,727 which issued Feb. 14, 1956 to Hensley for a Clean Row Fence Post; and U.S. Pat. No. 5,145,030 which issued Sep. 8, 1992 to Pavlescak et al for a Guard Rail Post.
Applicant notes that none of those references whether taken individually or collectively teach nor suggest a stanchion structure which, as described below allows a workman who is wearing a life line to walk along the uppermost surface of a concrete wall panel past stanchions supporting guardrails to which his life line is clipped.
In summary, the railing mounting device for mounting at least one flexible railing to concrete walls includes a stanchion. The stanchion may be releasably mountable to an anchor insert. The stanchion may be elongate and extend longitudinally between opposite first and second ends. The second end may have a mounting member mountable thereto so as to rigidly extend therefrom for sliding snug releasably securable mating engagement in a corresponding cavity in the anchor insert when the anchor insert is rigidly mounted into a concrete wall panel. The mounting member, when mounted to the stanchion, may lie generally in a first plane containing the first and second ends. The first end may be laterally offset in the first plane relative to the second end so as to extend over the mounting member in the first plane when mounted to the stanchion. A rail mount may be mountable to the stanchion towards the first end so as to releasably mount rails to the stanchion offset relative to the second end.
Without intending to be limiting, the rail mount may be at least one rigid substantially helical elongate member defining an eyelet along a longitudinal axis of a helix containing the helical elongate member. The longitudinal axis of the helix may be parallel to a flexible rail when the flexible rail is mounted into the eyelet. The eyelet may be sized so as to receive the flexible rail journalled therethrough. The helical elongate member may form a substantially helical loop. The helical elongate member may be rigidly mounted to the stanchion intermediately along the helical loop so that free ends of the helical loop extend away from the stanchion. The helical loop may be sized to allow passage of a life line clip ring sliding along the rail, firstly, so as to slide past a first free end of the free ends of the helical loop, secondly, so as to rotate the clip ring about the rail between the free ends of the helical loop so as to clear a second free end of the free ends of the helical loop, and thirdly, so as to slide past the second free end thereby passing the clip ring along the rail through the helical loop without unclipping the clip ring from the rail.
The at least one rigid helical elongate member may be a pair of helical elongate members spaced apart along a first portion of the stanchion extending between the first end and a laterally offsetting portion in the stanchion wherein the off-setting portion leg may laterally offset the first end from the second end.
Without intending to be limiting, in an alternative embodiment the rail mount may be at least one channel in the stanchion cooperating with a rail supporting bore in the stanchion, wherein the channel may be formed in the stanchion so as to be angularly offset, when the stanchion is mounted to the concrete wall, relative to a longitudinal axis of the flexible railing when the railing extends parallel to an upper edge of the concrete wall. The channel may be formed across the stanchion. The bore may be formed through the stanchion so as to intersect with the channel along its length. The at least one channel may include a channel formed diagonally in an uppermost surface of the first end. The bore may be substantially cylindrical. The channel may define substantially a parallelepiped. A lip may form at least one point of intersection between the channel and the bore for retaining the railing in the bore.
The anchor insert may be a tube mountable into a concrete slab wall. The mounting member may be a rigid cantilevered insert for snug sliding fitment into the tube. The cantilevered insert may be mounted to, so as to extend generally perpendicularly from, the second end of the stanchion without intending to be limiting, the tube may be a polygon in lateral cross-section therethrough and the cantilevered insert is correspondingly shaped in lateral cross-section, although it is intended to be within the scope of the invention that the stanchion be bolted to the concrete wall, the bolts engaging threaded inserts in the concrete. The offsetting portion may be positioned generally half-way along the stanchion. The first portion and second portion extend between the second end and the offsetting portion may be generally linear and parallel and have a first length and a second length respectively, and wherein the offsetting portion may have an elongate portion, angularly offset relative to the first and second portions.
In these alternative embodiments, not intended to be limiting, the elongate portion of the offsetting portion may extend a length not exceeding the length of either the first portion or the second portion, or may extend a length exceeding the length of either the first portion or the second portion, or may extend a length equal to the length of either the first portion or the second portion.